Technical Field
The present invention relates to an apparatus for replacing the welding tip of a spot welding gun. More particularly, the present invention relates to an apparatus for replacing the welding tip of a spot welding gun, which is capable of automatically replacing the welding tip of a spot welding gun.
Background Art
In general, in quantity production for a specific product as in a vehicle product line, spot welding in which a welding part has high stability is chiefly used because the heating time is very short and working speed is fast compared to other welding and residual stress or deformation is small due to a narrow heating range.
Spot welding is welding in which point bonding is performed on a sheet without perforating a hole in the sheet, such as a riveted joint, by generating melting in contact parts using the generation of heat according to electric resistance and bonding the contact parts using pressure.
In general, spot welding is performed using a robot on which a welding gun is mounted. The welding gun includes a body installed through the medium of a frame combined with a robot arm and configured to have a timer, a contactor, a transformer, etc. for welding embedded, a shank 1 installed to face the bottom of the body and the top of the arm rotatably installed in the body by a hinge shaft, and a welding tip (or a tip) 2 that is attached to the end of the shank 1 and at which welding is performed.
FIG. 1 is a diagram illustrating a conventional method of changing the tip of a robot welding gun.
In order to change the tip of a welding robot used in a current vehicle body manufacturing plant for vehicles, the tip is changed using a tool as illustrated in FIG. 1.
To this end, a worker drives a safety device before entering a vehicle body product line, stops the operation of the welding robot, and separates the tip 2 from the shank 1 of the welding gun of the robot using a pipe wrench or a tip-dedicated tool. Furthermore, a worker mounts a new tip using the tool, checks the new tip, drives the robot, and checks the state of the new tip.
When such a tip change task is performed, the time taken to replace a tip is relatively long because a worker enters the manufacturing line and directly changes the tip in a non-operation time. Furthermore, although safety conditions are thoroughly observed, there may be a problem in that a big accident is caused because another worker drives a robot, resulting in a safety problem.
Furthermore, since tip change workability is different depending on the location of the welding gun of the robot, it is inconvenient to move the welding gun to a place where a task is easy before replacing a tip. As a result, there is a disadvantage in that the working time is increased.
Furthermore, if a tip needs to be replaced when a vehicle body product line is driven, the operation must be stopped while a worker replaces the tip. Accordingly, there are problems in that productivity is reduced due to non-operation factors and personal expenses attributable to working hours are increased.
Furthermore, the prior art is problematic in that welding quality is deteriorated because the tip of the shank combined with the tip is deformed by external force that is generated when the tip is separated from the shank of the welding gun of the robot using a tool.